Composition for removing carbon deposits



Patented Mar. 6, 1934 PATENT. OFFICE- 1,949,588 comosmon ron anmovmc cacao nEPosrrs Charles A. Thomas and Carroll A. Hochwalt. Dayton, Ohio, assignors to Thomas & Hochwalt Laboratories, Inc., Dayton, Ohio, a corporation of Ohio No Drawing. Application July 18, 1930, Serial No. 468,990

12 Claims. (01. 87-5) This invention relates to compounds for removing carbon deposits such as are formed in internal combustion engine cylinders.

One of the principal objects of this invention is to provide a superior composition which is uni eflectve in removing such deposits.

Another object of this invention is to provide such a composition for removing carbon deposits which is quite cheap, and which has no objectionable deleterious effects upon metal parts with which it comes in contact. I,

other objects and advantages of the invention will be apparent from'the following description and appended claims.

Carbon deposits such as are formed in internal combustion engines are found to consist primarily of the following ingredients:

(1) Road dust, which consists principally of silica; (2) lubricating oil resulting from seepage 2 past the piston rings; (3) graphitic carbon which results primarily from cracking ofthegasoline and lubricating oil; and (4) oxidized lubricating oil "winch results from the oxidation of the ordinary lubricating oil which has seeped past the piston rings, this oil being oxidized at the high temperatures present in the cylinder and in the presence of oxygen of the fuel mixture. The oxidized lubricating oil, which comprises a number of complex and undetermined compounds of carbon, hy-

W droge'n and oxygen, forms a resistant binder or cement which binds the road dust and graphitic carbon together to hold them tightly onto the cylinder head, the piston top, and other portions cg the combustion space.

3 Various solvents, such as alcohol and benzol, which for purpose of description are hereinafter termed, low boiling organic solvents, have been used in an attempt to dissolve out such deposits. These solvents are found to have a solvent action upon the ordinary unoxidized lubricating oil but the oxidized lubricating ofl or binder is very resistant and is only dissolved to an ineffectual degree by such solvent.

We have dscovered that certain compounds,

namely the halogenated ethers, have a solvent action upon this binder. For example, the halogenated ethers, having the empirical formula CnH(2n+ll-x)Rx0, in which R represents a halogen, and :0 represents the number of substituted 59 halogen atoms, are very effective carbon removers. Thus beta-beta dichlor-ethyl ether,

which is ethyl ether containing two substituted chlorine atoms, is an excellent compound of this character. We have found that other ethers of this series containing a substituted halogen, such as dichlor-propyl ether, CsHIzChO; and dichlorbutyl ether CsHmChO; are satisfactory carbon removing compounds in accordance with this invention. v

Beta-beta dichlor-ethyl ether is a water white liquid, having a boiling point of 178C., sp. g. 20 of 1.213 and viscosity somewhat higher than that of water. We have found this compound to I be especially effective as a solvent for carbon deposits and in removing such deposits from engine cylinders.

In order to insure easy starting of an internal combustion engine after application of the carbon remover, a quantity of a highly volatile combustible is preferably incorporated in the composition. High test gasoline functions very satisfactorily for this purpose. a

An effective composition for removing carbon from engine cylinders may be prepared by using a mixture of beta-betaedichlor-ethyl ether with gasoline in the proportion of about 20% gasoline to 80% beta-beta-dichlor-ethyl ether.

While low boiling organic solvents, such as alcohol and benzol are relatively ineffective when used alone to remove carbon deposits such as are formed in engine cylinders, it has been found that a combination of such solvents with a material having more effective solvent action on the binder, produces a very effective carbon removing compo'sition. Such low boiling organic solvents dissolve any unoxidized lubricating oil in the deposit, and the more difllcultly soluble part of the binder is thus brought in direct contact with the more active solvent.

An effective carbon removing composition including such low boiling solvents is prepared as follows:

Percent I y weight High test gaso1ine 25 Denatured ethyl alcohol 25 Benzol- 25 Beta-beta dichlor-ethyl ether 25 M Another very effective composition for removing carbon deposits may be prepared without the use of gasoline, as follows:

In using this composition to remove carbon de-' posits from an internal combustion engine, the engine is first run until it is quite hot. Then the carbon remover is introduced into the cylinder, either by pouring through the intake manifold, care being taken to prevent escape of the solvent through the exhaust ports. Generally from about 20 to 50 0.0. are added per cylinder. The motor is then allowed to stand for some time, preferably about 6 hours or over night, during which time the composition acts upon the binder and renders the insoluble carbon and road dust free and flaky. The motor is then started and allowed to run a short time, the blast serving to blow the loosened solid material out through the exhaust.

It-is found that the action of this carbon remover is so eifective that carbon deposits on engine cylinders may be loosened to such a degree that objectionable knocking of the motor may result, due to the loosened deposits being jammed between the piston and valves and the cylinder head when the motor is again started. This is accentuated in certain types of high compression heads having irregular shape combustion chamber in which the clearance between the piston and head and the valves and the head is quite small at certain points or at one side thereof. With such a high compression head, it is found thatloosened carbon deposits may accumulate on the side having small clearance, when these loosened deposits are in a dry condition, and the movement of the piston and the valves during operation jams these deposits against the head with the result that a heavy knocking is produced, which in some instances may even be so serious as to result in cracking of the piston or the head. i

We have discovered that this knocking upon restarting of the engine after application of the carbon remover may be overcome by incorporating in the carbon remover a material having a high boiling point so that it is normally liquid at the high temperatures present in the engine cylinders, and which serves to keep the loosened carbon in a wet condition. We have found that such a heat resisting material serves to keep the carbon deposits in a mushy state and the objectionable knocking above referred to is eliminated, although the carbon deposit is eifectively discharged through the exhaust when the motor is started. An effective compound of this character is a low melting parafiin, or paraiiin oil, which does not readily evaporate at the high temperatures present within engine cylinders and is normally a liquid at these temperatures. Other high boiling compounds such as high boiling oils, or high boiling hydro-carbons such as naphthalene, function satisfactorily for this purpose. Such compounds also add lubricating properties, such that after use of the carbon remover the danger of the piston binding because of solution of the lubricating oil on the cylinder wall is minimized. High boiling chlorinated naphthalenes, such as mono-chlor-naphthalene, dichlornaphthalenes and tri-chlor-naphthalenes may be used for this purpose. Di-chlorbenzene is also satisfactory. These halogenated hydrocarbon materials are especially satisfactory because they withstand the heat of the motor without breaking down, and are also in themselves highly eiflcient carbon removers. Reference is herein made to the co-pending application of Charles A. Thomas and Carroll A. Hochwalt, Serial No. 397,144, filed October 3, 1929, which discloses and claims these halogenated hydrocarbons as carbon removers.

Many carbon removers are solids or semi-solids at ordinary temperatures. In order to make their application easy and effective, such compounds are dissolved in suitable solvents. Low boiling organic solvents such as the various alcohols, ether, acetone, ethyl acetate, kerosene, gasoline, benzene and the like, have usually been used, but these are in themselves ineffectual solvents of carbonaceous resinous deposits. Beta-betadichlor-ethyl ether, being itself a liquid at ordinary temperatures and having high solvent properties may be used very effectively as a carbon remover without the usual low boiling organic solvents.

As an example of a superior and preferable composition incorporating high test gasoline and a high boiling material to prevent knocking, the following may be used:

Per cent by weight High test gaso1ine 20 Denatured ethyl alcohol 20 Benzol 20 Mono-chlor-naphthalene 20 Beta-beta-dichlor-ethyl ether 20 While the compositions herein described constitute preferred embodiments of the invention, it is to be understod that the invention is not limited to these precise compositions and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. A composition for removing carbon deposits from engine cylinders comprising beta-beta dichlor-diethyl ether, denatured ethyl alcohol and benzol.

2. A composition for removing carbon deposits from engine cylinders comprising beta-beta dichlor-diethyl ether, denatured ethyl alcohol, mono-chlor-napthalene, benzol and high test gasoline.

3. A composition for removing carbon deposits from engine cylinders comprising a mixture of a low boiling organic solvent for lubricating oils with more than 10% by weight of a halogenated ether of the empirical formula CnH(2n+2-x)RxO, where R represents a halogen, and a: the number of substituted halogen atoms in the molecule.

4. A composition for removing carbon deposits from engine cylinders comprising as an essential ingredient a halogenated ether of the empirical formula CnH(2n+2x)RxO, where It represents a halogen, and a: the number of substituted halogen atoms in the molecule.

5. A composition for removing carbon deposits from engine cylinders comprising as an essential ingredient a chlorinated ether of the empirical formula CnH(2n+2x)C1x0, where :n represents the number of substituted chlorine atoms in the molecule.

6. A composition for removing carbon deposits from engine cylinders comprising a mixture of a low boiling organic solvent for partially oxidized lubricating oils with a chlorinated ether of the empirical formula CnH(2n+2x)C1xo, where n: represents the number of substituted chlorine atoms in the molecule.

7. A composition for removing carbon deposits from engine cylinders comprising a mixture of a low boiling organic solvent for partially oxidized lubricating oils with beta-beta dichlor-diethyl ether.

' 8. A composition for removing carbon deposits from engine cylinders comprising a high boiling point material of the group consisting of paraflln and paramn oils, mixed with a chlorinated ether of the empirical formula CnH(2n+2-J:)C1x0, where 2: represents the number of substituted chlorine atoms in the molecule.

9. A composition for removing carbon deposits from engine cylinders comprising a halogenated naphthalene, and a halogenated ether of the empirical formula CnH(2n+2x)Rxo, where R represents a halogen, and :r the number of substituted halogen atoms in the molecule.

10. A composition for removing carbon deposits from engine cylinders comprising a halogenated benzene, and a halogenated ether of the empirical formula CnH(Bn+2-X)Rx0, where R represents 

